public class TestMain <U,T>{
    private T t;
    private U u;
//    泛型类可能有多个参数，此时应将多个参数一起放在尖括号内。比如：<E1,E2,E3>

    public static void main(String[] args) {
        TestMain<String, Integer> testMain = new TestMain<>();
        testMain.t = 1;
        System.out.println(testMain.t);

    }
}
